JPS59168822A - Jar rice cooker with timer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric jar rice cooker that is used in general households and has the function of keeping warm and cooking rice, particularly an appliance that incorporates a timer that allows the rice cooking start time to be set. It is related to the circuit configuration.

Conventional structure and its problems In recent years, electric jar rice cookers used in general households that have heat retention and rice cooking functions use microcomputers to control the rice cooking process while adjusting the heat power etc. according to a certain program. There is a staff member who cooks rice.

The conventional microcomputer-equipped jar rice cooker mentioned above will be described below with reference to the drawings.

FIG. 1 shows an electrical circuit diagram of this conventional microcomputer-equipped jar rice cooker.

In Figure 1, 1 is a power plug, 2 is a power switch,
3 is a temperature fuse, 4 is a capacitor for noise reduction, 6 is a lid heater, 6 is a lower heater, 7 is a side heater, 8 is a relay contact for controlling the power of the lower heater, 9
10 is a rice cooking cooker operated by a heat-sensitive device placed in contact with the bottom of the pot to detect the start of rice cooking and the completion of rice cooking.
0 is a power semiconductor consisting of a series circuit for each heater when keeping warm, and a tria circuit that controls the power of the side heaters during rice cooking. 13 is a relay coil that operates the relay contact 8, 14 is an output section for operation display, etc., and 15 is a temperature input section from a heat-sensitive element in contact with the pot. 16,
17.18 is an L transistor, and 19, 20.21 are diodes.

22.24 is a resistor, and 23.25 is a capacitor.

About the jar rice cooker configured as above.

The operation is explained below when cooking rice without stirring.

After inserting the power plug 1 into the power source and turning on the power supply 2, turn on the rice cooking switch 9. The contact point opposite to 0 is 9.
a and 90 are connected.

Further, an electrolytic capacitor 23 is charged through a diode 19 and a resistor 22. This power supply supplies electricity to a drive control section consisting of a microcomputer 11, and starts operation. The output of microcomputer 11 is amplified by transistor 16 and ignites power semiconductor 10 . Similarly, relay coil 1 is connected by transistor 17.
3, flips the relay contact 8 from 8a to 8b side, and energizes the lower heater 6.0 At the beginning of rice cooking, while detecting the pot temperature using the temperature input section 15, the lower heater is turned on to keep the pot temperature constant. The heater 6 and the side heater 7 are energized to perform a submergence process. After a certain period of time has passed, the lower heater 6 and side heater 7 are fully energized. During this time, the amount of rice cooked is detected by detecting how the pot temperature rises. When the pot temperature exceeds a predetermined temperature, the lower heater 6 and the side heater 7 are turned on. 6 and the side heater 7 to adjust the firepower. After this, a heat-sensitive device placed at the bottom of the pot detects that the rice has been cooked, and the switch 9 switches from 9a to 9b.
The control continues. Next, we will explain the heat retention operation when the switch 9 is switched from the 9a side to the 9b side. When the switch 9 is turned on the 9b side, the resistor 24 and diode 20 are Then, the base current of the transistor 18 flows in the half wave of the power supply. The base circuit has a half wave smoothed by a capacitor 25, and the collector output of the transistor 18 becomes a DC signal, which can be input to the microcomputer 11 and performs a heat-retaining operation. In this case, the power semiconductor 10 is turned on according to the temperature of the pan from the temperature input section 15, and the series circuit of the lid heater 5, the lower heater 6, and the side heater Y is energized to perform the @4 control operation of keeping warm. It has become. Each operation mode is activated by emitting light from an LED or the like on the display unit 14.However, due to power reasons, in the circuit configuration as described above, the control circuit and heater circuit are connected in a complicated manner. Therefore, when installing a motor timer, it had the disadvantage that it could not be easily connected. Because.

If a timer is installed in the power supply path and the switch 2 is used as a contact point of the cooker, the power will be turned on after the time set by the timer has elapsed. Regardless of the timer setting, the power will be turned on after the timer setting has elapsed. Therefore, if the user forgets to turn on the rice cooking switch and sets the timer, the rice will simply keep warm after the timer set time has elapsed, causing the problem that the rice will not cook. It is.

Furthermore, in the configuration shown in FIG. 1, a switch 9 is used to switch between the rice cooking operation and the warming operation. At this time, only the base current of the transistor 18 flows through the contacts 9b - 9c K, but since the 9a side is switching a large current, there is a possibility that the contacts may be worn out or contaminated, resulting in poor contact. OBJECT OF THE INVENTION In view of the drawbacks of the conventional example, the present invention provides a jar rice cooker equipped with a drive control circuit having a microcomputer.
The purpose of this invention is to provide a specific circuit configuration that adds a motor timer and a specific configuration that inputs an input signal for rice cooking operation to a microcomputer.

Structure of the Invention In order to achieve the above-mentioned object, the present invention is characterized in that the timer rice cooker is structured as follows.

That is, a main body, a lid provided on the top surface of the main body so as to be openable and closable, a pot removably housed in one main body, a lower heater provided on the inner bottom of one main body, and a side heater provided on the inner surface of one main body.
A power semiconductor, a side heater, and a lower heater are connected to the common contact of the first switch, and the lid heater is connected to the normally closed contact of the first switch.
#@Next, connect to the power supply. The normally open contact of the first switch is connected to the power supply of the power semiconductor.

The connection points of the side heater and the bottom heater are connected to the timer motor via power control means. Furthermore, one end of the coil of the timer motor is connected to the connection point between the side heater and the lower heater, and the other end of the coil is connected to the power source through the other contact of the timer and the common contact l. DESCRIPTION OF EMBODIMENTS Five embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows an electric circuit diagram of a timer-equipped jar rice cooker according to an embodiment of the present invention. In Fig. 2, 30 is a power plug, 31 is a power switch, 32 is a temperature heater, 33 is a capacitor for noise reduction, 34 is a lid heater provided on the bottom surface of the lid, and 35 is provided on the inner bottom of the main body. 36 is a side heater; 37 is a timer motor coil; 38 is an electric contact for the timer; 39 is a relay switch that is turned on and off by the drive control unit; 40 is a relay coil; 41 is for starting and cooking rice. 42 is a power semiconductor such as a liac that controls the power of the heater; 43 is a microcomputer; 44 is an output display; 45 is a pot temperature input consisting of a heat-sensitive element in contact with the pot, etc. 46.47.48 is a transistor, 49.50°51 is a diode, 62 is a Zener diode, 63.64.66 is a capacitor +66.57
58 represents a resistor, and 58 represents a neon lamp.

The operation of the circuit configuration of the timer-equipped jar rice cooker configured as described above will be described below.

First, when the timer is at the time limit 0 point, the contacts 38C and 38A of the timer are connected.

Turn on the rice cooking switch 41 to set the rice cooking mode, and close the contact 41.
When b and 41c are connected, the power supply for the drive control circuit including the microcomputer is connected to the resistor 66 and the diode 48.
．． Capacitor 53. Resistor 57° Zener diode 52
．． It is created by the capacitor 54, and the relay contact 39 and the power semiconductor 42 are driven according to the rice cooking program.
The lower heater 35 and the side heater 736 are energized and rice cooking starts.0) After that, the microcomputer 4 performs a heating process using a small electric power for submerging the water and automatically determines the amount of rice to be cooked, etc. using a signal from the temperature input unit 45. 3 performs on/off control of the heater by the power control means.

When rice cooking is finished, the rice cooking switch 41 is opened. As a result, although the transistor 48 was turned off in the trench, a half wave of the power flows to the base through the diode 5o and the heater 34, and the transistor 48 is turned on. A time constant capacitor 55 is inserted in the base circuit of the transistor 48, and the output of the transistor 48 is a DC level signal, which is input to the microcomputer 43 to indicate that the operating mode has been switched. After this.

After the additional cooking process and the uneven cooking process, the process moves to the warming operation.

Next, when the timer is set, the timer contacts 38
38C and 38B are connected. At this time, plate switch 4
If 1 is on the heat retention side, the timer motor will not be energized and the neon lamp 68 connected to both ends of the motor coil will not light up.

On the other hand, turn on the rice cooking switch 41, and contact 41C and 41
When b is connected, the timer motor is connected to the power source via the lower heater 35, the timer is activated, and the timer set indicator lamp 58 is also lit. Broken contact 41
and 38A are open, power is not supplied to the control circuit, and there is no problem that only the microcomputer operates and the rice cooking process progresses without permission.

Effects of the Invention As described above, by connecting the timer contacts as in the present invention, the timer operation and timer set display are limited to when the rice cooking switch is turned on, so that the user can start cooking rice after the timer set time. In addition, since the rice cooking is controlled by a microcomputer, fluffy and delicious rice can be cooked.

Furthermore, it is equipped with a timer, which improves usability.

Since the input signal for the operation mode is taken from the part where the current flows in the closed control circuit, the contacts are cleaned, and even though the input is based on the base current of the transistor, it is highly reliable with fewer contact failures. can.

[Brief explanation of the drawing]

FIG. 1 is an electrical circuit diagram of a conventional jar rice cooker,
FIG. 2 shows an electric circuit diagram of a jar rice cooker with a timer according to an embodiment of the present invention. Name of agent: Patent attorney Toshio Nakao and one other person

Claims (1)

[Claims] A main body, a lid that can be opened and closed on the top of the main body, a pot that is removably housed in the main body, a lower heater provided on the inner bottom of the main body, a side heater provided on the inner surface of the main body, and a lid. The lid heater provided on the bottom surface, the N-force semiconductor, the side heater and the lower heater are connected in series to a common contact, a normally open contact connected to the power supply, and the lid heater connected to the power supply. a relay switch with a normally closed contact, and the connection point between the side heater and the bottom heater is connected to one contact of the timer via a power control means, and the connection point of both heaters is further connected to a timer motor. A jar rice cooker with a timer, which is configured such that an electric current is connected through the coil and another contact of the timer, and an input signal for a drive control section consisting of a microcomputer, a pot temperature detection device, etc. is obtained from the common contact of the relay switch. −